The efficacy of (3-amino-1-hydroxypropylidene)-1,1-biphosphonate (APD) is reported in a severe case of osteogenesis imperfecta (OI). An increased density at the metaphysis level is demonstrated on wrist radiograph. Similar findings have been observed in two other children with OI at various metaphyseal levels (e.g., tibia, femur). To our knowledge, this is the first time the effect of APD in children with severe OI has been reported.